The "Xerd" of the game's title is a hero who defeated evil 800 years in the past. You control another character (default name Jake), prince of the one of the kingdoms, to defeat his evil twin brother by hunting down the reincarnation of the legendary hero.
There used to be a continent called "Mu Continent", which was ruled by the king of the country called Prina. King Lars II suddenly turned the state religion of Neil into the evil religion of Max. Shortly after the Neil people were ousted from the sanctuary, the Queen of Purina suddenly disappeared. In addition, the newborn son of the king was taken away by someone. After the conversion, monsters began to appear in various parts of the continent. People began rumors that the people of Neil were manipulating monsters. It's been 16 years since then. The demons, who continued to grow in power, finally invaded Purina Castle. The seriously injured king runs to the remote village "Eribe".
Despite many sources claiming that Tenchi wo Kurau for Game Boy is a port of the NES original, it’s actually a totally new game. It’s not even developed by Capcom, but instead Sun L, the developer responsible for the Game Boy ports of Gargoyle’s Quest II and Street Fighter II. Tenchi wo Kurau follows a similar storyline to the previous entries, but reshuffles things in interesting ways. Rather than starting with Zhang Fei, Liu Bei, and Guan Ye’s blood oath, you begin only as Liu Bei. The initial hour of gameplay involves finding his companions, joining up with the army, and destroying the Yellow Turbans.
In an internal Rare document of games that were to be shown at E3 1998, one listing is for D.K.R. DMG, with D.K.R. likely standing for Diddy Kong Racing and DMG referring to the Game Boy. The game was never publicly shown.
Unova Red is a re-imagining of Generation 1, but using the Pokedex from Generation 5. This is because the Unova Pokedex was designed to stand alone without any Pokemon from additional regions, much like the original Pokedex. The plot is effectively identical to the Generation 1 games, the only major change is in the Pokemon available. There is also a challenge mode patch which provides a more difficult version of the same hack.